Viruses, such as parvovirus or coronavirus, which commonly spreads through exposure to feces from an infected dog.

Bacteria, such as Campylobacter, Salmonella, E. coli, Clostridia, which can be contracted via food poisoning and may be passed on from animal to human.

Parasites and worms are typically transmitted when a dog eats the stool of an infected dog or cat.

Pancreatitis, caused by an inflamed digestive gland, by medications or consuming something that’s difficult for the pancreas to handle, such as a meal high in fat.

Common Causes of Chronic Digestive Disorders in Dogs

IBD (inflammatory bowel disease), which still has an unknown cause, Johnson explains. “It is manageable but not curable. Dogs with [IBD] have periodic flare-ups when you have to intensify their therapy.”

Hemorrhagic gastritis, which induces profuse vomiting and bloody diarrhea, is caused by infectious agents such as bacteria, viruses, fungi, and parasites; it can also be due to a bad reaction to certain medications.

For the complete slideshow on digestive problems in dogs: causes, signs and treatments, visit petMD.